Hydrocarbon oils having improved water tolerance



Nov. 14, 1961 J. R. SIEGEL 3,008,813

HYDROCARBON OILS HAVING IMPROVED WATER TOLERANCE Filed Oct. 29, 1958EFFECT OF DICOCO DIMETHYL AMMONIUM CHLORIDE UPON HAZE SETTLING RATE 25 II I CONTAINING N0 DICOCO DIMETHYL l AMMONIUM CHLORIDE /.HAzE

l0 on. CONTAINING 0.0005 WT.%

0|c0c0 DIMETHYL AMMONIUM CHLORIDE O l I l I l I I0 '30 40 so HOURSSETTLING doel R. Siege! Inventor By gm a, Li Ahorney United StatesPatent Filed Oct. 29, 1958, Ser- No. 770,520 12 Claims. (CI. 4462) Thepresent invention relates to improvements in the water tolerance ofhydrocarbon oils and more particularly relates to petroleum distillatefuels and similar hydrocarbon oil products having incorporated thereinadditive agents singularly adapted to prevent the formation ofpersistent haze and stable emulsions when such products are contactedwith water during handling and storage.

Ashless oil-soluble polymeric dispersants have largely displaced metalsulfonates, metal naphthenates and similar compounds for use asstabilizing additives in petroleum distillate fuels and relatedhydrocarbon oil products because of their increased ability to suspendinsoluble degradation products formed in such oils. Sludge and sedimentwhich might otherwise tend to clog fuel lines, orifices, screens andfilters through which the oils must pass are held in suspension to amuch greater extent by the polymeric additives than by the additivematerials formerly employed. These increased dispersive properties,although highly desirable from the standpoint of oil stability, havegiven rise to water tolerance problems much more serious than thoseheretofore encountered. The polymeric materials employed as oilstabilizing addi-tives exhibited particularly pronounced tendencies tosuspend any water with which the oils come into contact and henceextremely persistent haze and stable emulsions are formed upon contactof oils containing the polymeric additives with water. Since an aqueousphase exists in most tanks and other vessels containing such oils, hazeformation and emulsification are almost impossible to avoid. As aconsequence, the marketability of distillate fuels, lubricating oils,transformer oils, turbine oils and other petroleum distillate productsin which polymeric dispersants are used is often seriously affected.

The present invention provides a class of new and improved additiveswhich are surprisingly effective for increasing the water tolerance ofpetroleum distillate fuels and similar liquid hydrocarbon oilscontaining polymeric dispersant additives. In accordance with theinvention, it has now been discovered that the addition of minor amountsof certain quaternary ammonium compounds to such oils greatly reducesthe persistence of haze and emulsions formed when the products arecontacted with water and thus permits their transportation and storagein the presence of an aqueous phase without adverse results.

The quaternary ammonium compounds which have been found to be singularlyeffective for improving the water tolerance of petroleum products inaccordance with the invention are dialkyl dimethyl ammonium chlorideshaving alkyl groups which each contain from 12 to 14 carbon atoms. Ithas been found that compounds of this type are critical for purposes ofthe invention. Closely related tetraalkyl ammonium chlorides such as thetrialkyl monomethyl ammonium chlorides and the monoalkyl trimethylammonium chloride are not effective for reducing haze and emulsionformation, are readily extracted by water, adversely affect the actionof the polymeric stabilizing additives, or are otherwise unsuitable forpurposes of the invention. Specific examples of dialkyl dimethylammonium chlorides which may be employed are didodecyl dimethyl ammoniumchloride, ditridecyl dimethyl ammonium chloride, dodecyl tridecyldimethyl ammonium chloride, dodecyl tetradecyl dimethyl ammoniumchloride and tridecyl tetradecyl dimethyl ammonium chloride. Also usefulfor purposes of the invention are dialkyl dimethyl ammonium chloridesderived from naturally occurring materials such as coconut oil whichcontain at least 50% by weight of C to C alkyl groups. Dicocodimethylammonium chloride, derived from coconut oil, contains from about 55 toabout 70% of C to C alkyl groups and has been found eminentlysatisfactory for purposes of the invention. The alkyl groups outside theC to C range in these mixed dialkyl dimethyl ammonium chloridesapparently do not contribute to the improved water tolerance of theproducts to which the chlorides are added but appear to have no adverseeffect. Such mixed dialkyl dimethyl ammonium chlorides are generallyreferred to as technical dilau'ryl dimethyl ammonium chlorides and arereadily available from corrnnercial sources. Such mixtures are thereforepreferred for purposes of the invention.

The polymeric dispersant additives primarily responsible for the poorwater tolerance of distillate fuels and similar products are widely usedcommercially and are well known to those skilled in the art. Thesedispersants in general are polymers and copolymers of unsaturatedorganic esters, nitriles and similar monomers containing vinyl, vinyleneor vinylidene linkages. The dialkyl dimethyl ammonium chlorides employedin accordance with the invention have been found effective when used inoils containing a wide variety of such polymeric dispersants.

A class of polymeric dispersant additives in conjunction with which thedialkyl dimethyl ammonium chlorides have been found to be particularlyeffective are those which are prepared by the copolymerization of analkyl chloropropyleneoxy mixed ester of an unsaturated conjugateddibasic acid with a polymerizable organic monomer containing a vinyllinkage. The alkyl chloropropyleneoxy mixed esters used as one of thecomponents of such copolymers are prepared by'first reacting a C to Cunsaturated conjugated dibasic acid such as maleic acid, fumaric acid,citraconic acid, mesaconic acid or a mixture of such acids or theiranhydrides,,when they exist, with a long chain saturated aliphaticalcohol to produce a half ester. Suitable-alcohols for this purpose arethose containing from about 8 to about 24 carbonatoms per molecule,preferably about 8 to 18 carbon atoms per molecule. Straight chainprimary alcohols such as dodecyl, cetyl, eicosyl and docosyl alcoholsare preferred but branched chain alcohols such as 2-ethy1hexanol-1 and Coxo-alcohols, secondary alcohols such as caprylalcohol and mixtures ofstraight and branched-chain alcohols may also be used. Commerciallymarketed mixtures of alcohols of the requisite chain length, such asthose obtained by the hydrogenation of coconut oil may also be used.

.may range from about 1:1 to 1:4. Addition of the epichlorohydrin takesplace throughthe epoxy group and the chlorine atom is unaffected. Themixed ester may thus contain from 1 to about 3 chlorine atoms.

The mixed ester prepared as described above is then copolymerized withfrom about /2 to about 2-0 parts of an unsaturated organic monomercontaining a vinylfg'roup in the presence of gamma radiation, a peroxidetype catalyst such as benzoyl peroxide, or an azo catalyst such asalpha-alpha azo-bis-isobutyronitrile. Suitable mono mers containingvinyl groups include hydrocarbons such as styrene, isobutylene andbutadiene'; esters such as vinyl propionate and methyl methacrylate;ethers such as divinyl ether; and nitriles such as acrylonitrile andvinylacetonitrile. Mixtures of such monomers containing materials.

' forrnates,

vinyl groups with other copolymerizable materials, long chain alcoholesters of unsaturated conjugated dibasic acids such as lauryl maleateand tallow fumarate for example, may also be used. Vinyl esters of shortchain fatty acids, particularly vinyl acetate and mixtures of suchesters with fumarate or malea-te esters of long chain aliphatic alcoholscontaining from about 8 to about 20 carbon atoms per molecule arepreferred monomers for preparation of the copolymers with the mixedesters.

The resulting copolymers are oil-soluble and preferably have molecularWeights between about 6000 and about 20,000 Staudinger. Such copolymersare described in copending application S.N. 673,156, filed July 22,1957.

A second class of polymeric dispersant additives with which the dialkyldimethyl ammonium chlorides are es pecially effective are oil-soluble,nitrogen-containing addition type copolymers prepared by copolymerizingan amine-free monomer containing one polymerizable ethylenic linkage andan aliphatic hydrocarbon chain of from 8 to 18 carbon atoms with amonomer containing a nitrogen atom and one polymerizable ethyleniclink-age. Such copolymers may be prepared, for example, by thecopolymerization of an acrylic or alpha-substituted acrylic ester of analiphatic alcohol containing an average of from 8 to 18 carbon atoms,such as lauryl methacrylate, with an ethylenically unsaturated compoundcontaining a basic amino group, such as beta dimethylamino-ethylmethacrylate. Other specific examples of the amine-free monomerscontaining a polymerizable ethylenic linkage and a C -C aliphatic chaininclude the tridecyl, cetyl and octadecyl esters of acrylic andmethacrylic acids. Also suitable are esters of these acids prepared frommixtures of alcohols such as those containing primary alcohols of from10 to 18 carbon atoms derived by the hydrogenation of coconut oil andsold under the trade name Lorol. A typical mixture consists chiefly oflauryl alcohol having 12 carbon atoms per molecule and has the followingapproximate composition:

Alcohol constituent- Weight percen c rr orr 4.0 C12H25OH 55.5 c rr orr22.5 c n ou 14.0 c rr orr 4.0

in addition to those described above may be incorporated into thecopolymers of the second preferred class as filler Such filler materialsinclude vinyl and allyl acetates, propionates; isobutylene; styrene;methyl meth-acrylate; ethyl vinyl ether and the like. The finalcopolymer may contain from about 20% to about 99% of the nitrogen-freemonomer, from about 0.5% to 50% of the nitrogen-containing monomer, andfrom about 0 to about 79% of the monomer used as a filler material. Manyof the polymeric additives falling within the second preferred classdescribed above are de scribed in detail in US. Patent No. 2,737,452,issued March 6, 1956.

Polymeric dispersant additives of the second class described above aresometimes employed in combination with tertiary alkyl primary amine-s.Although such amines do not have pronounced dispersant properties,

they effect a considerable improvement in the stabilizing action of thenitrogen-containing polymeric dispersants. They do not, however,overcome the tendency of such dispersants to suspend water in oils inwhich they are present and hence do not prevent the water toleranceproblem caused by the dispersanrts. The dialkyl dimethyl ammoniumchlorides may therefore be employed to advantage in oils containing botha polymeric dispersant and a tertiary alkyl primary amine.

The tertiary alkyl primary amines useful with the polymeric dispersantsdescribed above in general are those having two alkyl groups of from 1to 3 carbon atoms attached to the tertiary carbon atom and one alkylgroup of from 5 to 21 carbon atoms attached to the tertiary carbon atom.Tertiary alkyl primary amines containing a total of from 8 to 18 carbonatoms per molecule are preferred. Particularly preferred are C tertiaryalkyl primary amines. Mixtures of such amines such as those derived frompolyolefins may also be used.

Tertiary alkyl primary amines such as those described above aregenerally employed in combination with the nitrogen-containing polymericdispersants in concentrations such that the ratio of amine to dispersantin the oil ranges from about 2 to 1 to about 18 to 1. Amineconcentrations between about 0.003 wt. percent to about 0.8 wt. percentare especially effective.

Many other polymeric dispersant additives suitable for the stabilizationof hydrocarbon oils will be familiar to those skilled in the art. Thestabilization of haze and emulsions is a universal property of suchdisperant additives and the dialkyl dimethyl ammonium chlorides may beemployedwith a wide variety of such materials. Representative examplesof other ashless, oil-soluble polymeric stabilizing additives aredescribed in US. Patent 2,737,496 to Catlin; in US. 2,800,452 to Bondiet al.; and in application SN. 690,184, filed October 15, 1957, now US.Patent 2,958,590.

The oils in which the additives of the invention may be incorporated areliquid petroleum distillate products boiling in the range between about75 .and about 900 F. Such products include gasolines, aviation turbo-jetfuels, kerosenes, diesel fuels, transformer oils, turbine oils, heatingoils, and lubricating oils. The additives are particularly effective indistillate fuels boiling in the range between about 250 F. and about 750F. Such fuels include turbo-jet engine fuels, diesel fuels and heatingoils which have particularly poor stability properties and require theuse of relatively large amounts of the polymeric dispersant additives.Aviation turbo-jet engine fuels are defined by US. MilitarySpecifications MIL- F 5624C, MIL F-25524A, and MIL F 2258A and aregenerally referred to as IP4, JP-5 and IP-6.

. 'Diesel fuels in connection with which the additives of the inventionare particularly useful are more fully dedescribed in ASTM SpecificationD-97553T and may be used in stationary, marine and automotive typeengines. Typical of the heating oils in which the additives may beemployed are those described in ASTM Specification D396-48T,particularly those in grades 1 and 2 thereof.

The polymeric dispersant additives are generally employed in petroleumhydrocarbon products such as those described above in concentrationsranging from about 0.001% and about 1% by weight. Concentrations of from0.001% to 0.05% are generally preferred. The dialkyl dimethyl ammoniumchlorides which are used in such oils may be incorporated therein inconcentrations in the range of from about 000025 wt. percent to about0.0 1 wt. percent. Chloride concentrations in the range of from about0.0005 wt. percent to about 0.001 wt. percent have been found to begenerally effective and are preferred, since it has been found that thestabilizing properties of some dispersant additives may suffer when thedialkyl dimethyl ammonium chlorides are present in very highconcentrations.

-measuring the volume of the emulsion phase.

' lows:

The ammonium chloride compound may be incorpor-ated into the fuels bydissolving them in a suit-able solvent such as 'isopropanol, butanol,benzene or the like and then adding the resultant solution to the oil inquantities sufiicient to give the desired additive concentrations. Ifdesired, additive concentrates containing both the polymeric dispersantstabilizing additive and the dialkyl dimethyl ammonium chloride compoundin a suitable solvent may be prepared. Other additive materials commonlyused in the products to which the concentrate is to be added may also beincluded in such concentrates. Such other additive materials maycomprise rust inhibitors, anti-static additives, corrosion inhibitors,dyes, dye stabilizers and the like. i

The invention may be further illustrated by the following examples andthe accompanying drawing.

EXAMPLE 1 Samples of a petroleum distillate heating oil which had beenstabilized by the inclusion therein of 0.01% by weight of variouspolymeric dispersant additives were tested to determine the persistenceof the haze formed when the fuel was contacted with water and thestability of the emulsions formed during such contacting. The fuelemployed was .a blend consisting of about 50% by volume of virgin gasoil and about 50% by volume of catalytically cracked stock. Typicalinspections for a fuel of this type are as follows:

Conradson carbon residue, wt. percent 0.006

The persistence of the haze formed in this oil upon contact with waterwas measured in Waring Blendor haze tests wherein five milliliters ofwater and 500 milliliters of the oil were mixed in a Waring Blendor fora period of five minutes, the oil-Water mixture was then allowed tostand for six hours, and the amount of light which was transmittedthrough the oil under standardized conditions was measured. :The lighttransmission was expressed as a percentage of the total light emittedfrom the source. This test has been found to be an extremely effectivemeans for determining the degree to which haze is present in hydrocarbonoils and is recognized as reliable throughout the petroleum industry.

Herschel emulsion tests were carried out to determine the effect of theadditives upon emulsification by stirring 40 millilters of oil and 40milliliters of water for five minutes at a temperature of 77 F. to forman emulsion, letting the mixture stand for 15 minutes, and then Similartests are widely used'for determining the emulsification tendencies ofturbine oils in accordance with ASTM Standard D-1401-56T and in similarapplications.

Three different tetraalkyl ammonium chlorides were added inconcentrations of 0.0008 wt. percent to separate samples of the sameheating oil containing 0.01 wt. percent of the same polymeric dispersantadditive. The tetraalkyl ammonium chlorides employed were as fol- (1)Dicoco dimethyl ammonium chloride-a dialkyl dimethyl ammonium chloridehaving mixed alkyl groups derived-from coconut oil as follows: 8% Cradicals, 7% C radicals, 48% C radicals, 18.5% C radicals, 8% Cradioalsand 10.5% C radicals.

" (2) Disoya dimethyl ammonium chloride-a dialkyl dimethyl ammoniumchloride having mixed alkyl groups derived from soybean oil whichinclude about 8% C radicals, about 88% C radicals and about 4% Cradicals.

(3) Dihydrogenated tallow dimethyl ammonium chloride-a dialkyl dimethylammonium chloride having mixed C and C alkyl groups derived fromhydrogenated tallow.

I (4) Tallow trimethyl ammonium chloride- -a monoalkyl trimethylammonium chloride having mixed C and C alkyl groups derived from tallow.

The oil samples containing the polymeric dispersant additive and theabove tetraalkyl ammonium chlorides were than subjected to WaringBlendor haze tests and Herschel emulsion tests, both with and withoutprior water extraction. About 1% water was used in the water extractionstep. The results obtained in these tests are in Table I.

Table I EFFECT OF TETRAALKYL AMMONIUM GHLORIDES UPON HAZE ANDEMULSIFICATION IN HEATING OILS Waring Blendor Herschel emulsion hazetest, percent test, milliliters light transmission emulsion after 15after 6 hours minutes Fuel Fuel not Fuel ex- Fuel not Fuel exwaterextreated water extracted tracted with tracted with water water Baseheating oil 94 0 0 Base heating oil+0.01% additive A 1 14 12 4 31 Baseheating oil+0.01% additive A+0.0008% dicoco dimethyl ammonium chlori e95 81 l 2 Base heating 0i1+0.01% additive A+0.0008% disoya dimethylammonium chloride 54 30 3 18 Base heating oil+0.01% additive A+0.0008%dihydro- I genated tallow dimethyl ammonium chloride 53 12 18 15 Baseheating oi1+0.01% additive A+0.0008% tallow trimethyl ammonium chloride90 6 Base heating oil+0.01% additive B 2 48 64 Base heating 0il+0.01%additive B+0.0008% dicoco dimethyl ammonium chloride 92 88 Base heatingoil+0.01% additive B+0.0008% disoya dimethyl ammonium chlo- I ride 36 60Base heating oi1+0.01% additive B|-0.0008% dihydrogenated tallowdimethyl ammonium chloride 29 27 Additive A was a copolymer of 1 mol ofvinyl acetate, 0.25 mol of isooctyl chloropropyleneoxy maleate, and 0.75mol of mixed 0 5-0 alkyl iumarates, 50 weight percent concentration inbenzene.

2 Additive B was a mixture of 8 parts of a C1 tertiary alkyl primaryamine and 1 part of a copolymer prepared from 8 parts of Lorolmethacrylate and 2 parts of beta diethylaminoethyl methacrylate.

From the Waring Blendor test results in the above table it can be seenthat the light transmission through the base heating oil containing thepolymeric dispersant additive was quite low, indicating a high hazelevel. The fact that this haze persisted even though six hours hadelapsed between the time the water and oil were mixed and the time thelight transmission values were determined shows that it wasexceptionally stable due to the presence of the polymeric dispersant inthe oil. The results obtained with the samples containing the dicocodimethyl ammonium chloride demonstrate the remarkable effectiveness ofthis additive for preventing the formation of persistent haze in oils.This effectiveness is particularly outstanding in view of the fact thatthis material is marketed commercially for use as a general emulsionstabilizer and might therefore be expected to promote,

rather than hinder, the formation of persistent haze. The disoyadimethyl ammonium chloride and the dihydrogenated tallow ammoniumchloride, both of which have structures very similar to that of dicocodimethyl ammonium chloride but do not contain predominantly C and Calkyl groups, were much less efiective. I Results of the Herschelemulsion tests confirm these findings. The above data also demonstratethat the eifectiveness of dicoco dimethyl ammonium chloride is notseriously raffected by water extraction. The disoya dimethyl =ammoniumchloride and the dihydrogenated tallow ammonium chloride, on the otherhand, were much less effective after water extraction.

The data obtained with tallow trimethyl ammonium chloride demonstratethat a satisfactory additive must not be extracted by water to anysignificant extent. The tallow trimethyl ammonium chloride was largelyremoved from the fuel during the extraction step and hence affordedlittle protection against the formation of persistent haze when the fuelwas subsequently subjected to the Waring Blendor test. The dicocodimethyl ammonium chloride, on the other hand, was extracted only to aslight degree and was nearly as effective following the water extractionstep as it was prior to water extraction. Since distillate fuels andother petroleum products in which polymeric dispersant additives arefrequently employed are often contacted with relatively large quantitiesof water under conditions which may lead to the extraction of additivescontained therein, this difference between the dicoco dimethyl ammoniumchloride and the tallow trimethyl ammonium chloride is a significantone.

EXAMPLE 2 In order to determine the effectiveness of commercialdemulsifiers for use in oils containing polymeric dispersant additives,tests similar to those described above were carried out upon samples ofheating oils containing such inhibitors. The heating oils employed hadproperties similar to those of the oil used in the preceding example andcontained polymeric dispcrsants in 0.01 wt. percent concentrations. Thesamples were first subjected to Waring Blender haze tests. If theresults from this test indicated that the particular inhibitor showedpromise, Herschel emulsion tests were carried out. The overall resultsobtained are summarized as follows.

Table II NorE.For footnotes 1 and 2 see Table I.

Tests were carried out on 70 other commercial demulsifiers by adding0.005 wt. percent of the material to be tested to 250 ml. of heating oilcontaining 0.01 wt. percent of polymeric dispersant B, shaking theSample with 1% 'Water, and

then usually observing rate at which the haze cleared. Sixty-three ofthese commercial additives were found to promote haze in the presence ofthe polymeric dispersant, six had no visible influence upon the hazingproperties of the oil containing the dispersant, and one indicated aslight improvement in haze clearing rate. When this latter additive wasretested, the results could not be duplicated.

EXAMPLE 3 Tests were carried out to determine the eifect of dicocodimethyl ammonium chloride upon the stability of distillate petroleumproducts. The test employed was the accelerated storage stability testdescribedin detail in New Fast Test Method for Distillate StorageStability, by W. A. Konrad, N. L. Shipley and T. S. Tutwiler on page ofPetroleum Processing for September 1946. Briefly, the accelerated filterplugging test consists of heating a sample of the oil to be tested at acontrolled rate for L6 hours to a final temperature of 230 F. in orderto accelerate the formation of sediment in the oil. The oil sample isthen cooled and passed through a felt filter pad at a constant rate of 1gallon per hour. As sediment accumulates on the filter under constantoil flow conditions, the pressure drop across the filter increases.After 12 liters, the Standard Volume used in the test, has beenfiltered, a record is made of final pressure drop across the filter, theweight of sediment collected is determined, and the appearance of thefilter is noted. These criteria are individually interpreted on ademerit basis wherein 0 is an excellent rating and 10 is a very badrating. The values for the 3 criteria, final pressure drop, Weight ofsediment and appearance, are averaged arithmetically to obtain theoverall accelerated filter plugging test demerit value for the oil.Results obtained in this test are reproducible to :03.

The oil employed in the accelerated filter plugging tests was a heatingoil having properties substantially the same as those of the oildescribed in Example 1. Tests were also made on samples of this oilcontaining the polymeric dispersant additives described in Examples 1and 2 and upon samples containing both the polymeric dispersantadditives and dicoco dimethyl ammonium chloride. Table III.

Table III EFFECT OF DICOCO DIMETHYL AMMONIUM CHLORIDE ON FUEL STABILITYAccelerated Fuel filter plugging test overall demerit Base heating oil9. 3 Base heating oil+0.01% polymeric dispersant A 1 l 0 Base heatingoil+0.0l% polymeric dispersant A 0.0005% dicoco dimethyl ammoniumchloride- 0. 7 Base heating oil+0.01% polymeric dispersant A 0.001%dicoco dimethyl ammonium chloride 1.3 Base heating oil+0.01% polymericdispersant B 1 1.0 Base heating oil+0.0l% polymeric dispersant B 0.001%dicoco dimethyl ammonium chloride 1 0 1 Polymeric dispersant A was acopolymer of 1 mol. of vinyl acetate, 0.25 mols. of isooctylohloropropyleneoxy maleate, and 0.75 mols. of mixed ole-O13 alkyliumarate. 50% concentration in benzene.

2 Polymeric dispersant B was a mixture of 8 parts of a Cu tertiary alkylprimary amine and 1 part of a copolymer prepared from 8 parts of Lorolmethacrylate and 2 parts of beta diethylaminoethyl methacrylate.

Fro-m the foregoing table it is evident that the addition of dicocodimethyl ammonium chloride to petroleum distillate fuels and productscontaining polymeric dispersant additives does not adversely eifect thestability of such fuels or interfere with the stabilizing action of thepolymeric additives. At the concentrations in which they are used, theammonium chloride compounds reduce the ability of the dispersants tosuspend water but do not reduce their ability to suspend insolublereaction products formed in the oil. The data in Table III sug- Theresults of these tests are set forth in gest that in some instances itmay be preferred to limit the amount of dicoco dimethyl ammoniumchloride added to oils containing polymeric dispersant stabilizingadditives to about 0.001 wt. percent or less. The demerit rating of thesample containing 0.01% of dispersant A and 0.0005% of the chloride wasslightly better than that of the sample containing the same amount ofthe polymeric dispersant and 0.001% of the chloride. The data areconsistent within the reproducibility of the test.

EXAMPLE 4 Table IV EFFECT OF EXTRACTION WITH PIPELINE INHIBITOR UPONTETRAALKYL AMMONIUM CHLORIDE HAZE PREVENTIVE Percent light transmissionafter 6 hrs. Fuel following extraction with pipeline inhibitor solution1 Base fuel+0.01% polymeric dispersant B 2 51 Base fuel-{001% polymericdispersant B +0.00076% dicoco dimethyl ammonium chloride Base fuel+0.0l%polymeric dispersant B +0.00068% dicoco dimethyl ammonium chloride 90Base fuel+0.01% polymeric dispersant B +0 00060% dicoco dimethylammonium chloride 84 Base iuel+0.01% polymeric dispersant B +0 005%dicoco dimethyl ammonium chloride 96 The inhibitor was an aqueoussolution used commercially for preventing pipeline corrosion andconsists of 720 gms. of NBNO: and 8.6 gms. of N aOH in 2,000 ml. ofdistilled water.

1 See footnote 2, Table III.

The above data demonstrate that the aqueous pipeline inhibitor solutiondid not extract the dicoco dimethyl ammonium chloride from the fuel toan appreciable extent and hence did not increase the tendency of thefuel to form persistent haze when subsequently contacted with water. Theresults shown above also show the effect of varying the concentration ofthe dicoco dimethyl ammonium chloride and indicate that the additive isparticularly eifective at concentrations of about 0.0005 wt. percent.

EXAMPLE 5 the oil in the Waring Blendor. The results of these tests aresummarized in Table V and it can be seen that the addition of thechloride after haze formation had no effect whatsoever.

a Base heating 0il+0.005% polymeric dispersant 13 I Table V EFFECT OFADDITION OF DICOOO DIMETHYL fihA/[ZMEONIUM CHLORIDE TO FUELS CONTAININGWATER- Waring Blender haze Fuel test, percent light transmission after 6hrs.

Base heating oil+0.01% polymeric dispersant B 1 4 Base heating oil+0.017polymeric dispersant B 0.0005% dicoco dimeth yl ammonium chloride addedafter haze formation 4 Base heating oil+0.005% polymeric dispersant B 15 0.0007595 dicoco dimethyl ammonium chloride added after haze fnrmntinn5 1 Polymeric dispersant B was a mixture of 8 parts of a C tertiaryalkyprimary amine and 1 part of a copolymer prepared from 8 parts ofLorol methacrylate and 2 parts of beta diethylaminoethyl methacrylate.

EXAMPLE 6 In order to further test the eifectiveness of dicoco dimethylammonium chloride, full-scale tanker tests were carried out bytransporting 140,000 barrels of heating oil containing 0.005 wt. percentof a polymeric stabilizing additive in an ocean-going tanker from theGulf coast to a New Jersey port. The additive employed was a mixture of8 parts of a'C tertiary alkyl primary amine and 1 part of a copolymerprepared from 8 parts of Lorol methacrylate and 2 parts of betadiethylaminoethyl methacrylate. About 80,000 barrels of the oilcontained 0.0005 wt. percent of dicoco dimethyl ammonium chloride. Thisoil was transported in 7 tanks of the ship. The remaining 60,000 barrelsof oil was free of haze inhibitor and was transported in 12 tan-ks ofthe ship. There was about 4 inches of water in the bottom of each tank.

Upon completion of the voyage, the oil containing, the dicoco dimethylammonium chloride and the oil free of the inhibitor were pumped intoseparate shore tanks of 112,000 barrels capacity. Hourly haze readings(percent haze equals 100 percent transmission relative to fuel filteredbright) were made during the pumping at (1) the line on the dock (2) theline on the shore, and (3) the receiving tank. Haze readings on the lineat the dock showed initial values of to with and without the ammoniumchloride. The haze thereafter leveled 01f during pumping at from 45 to 50% in the oil which did not contain the additive of the invention;whereas haze in the oil'con taining the additive leveled off at from 7to 8%. The other haze readingsshowedsimilar advantages for the additive.

After completion of the pumping described above, settling of the haze inthe two shore tanks was observed at intervals for several days. Theresults of these observations are shown in the attached drawing. As canbe seen from the drawing, the oil containing the dicoco dimethylammonium chloride had settled to 10% haze in 20 hours and contained only1% haze after 62 hours. After 64 flours the oil without the additive hadleveled off at 11% aze.

EXAMPLE 7 A turbo-jet engine fuel boiling between 275 F. and 480 F.contains 0.02 wt. percent of a copolymer of 50 parts of decylmethacrylate, 30 parts of octadecyl styrene and 20 parts of 4-vinylpyridine as a polymeric dispersant stabilizing additive. The watertolerance properties of this fuel are improved by the addition of 0.002wt. percent of didodecyl dimethyl ammonium chloride.

EXAMPLE 8 A diesel fuel is stabilized by theincorporation therein of0.01 wt. percent of a copolymer of 80 parts of lauryl acrylate and 20parts of beta methylamino butyl vinyl ether and 0.08 wt. percent of amixture of tertiary alkyl 1 1 primary amines derived from C to Cpolypropylene. To this fuel is added 0.008 wt. percent of dodecyltetradecy-l dimethyl ammonium chloride in order to improve its watertolerance.

The preceding examples illustrate the efiect of dicoco dimethyl ammoniumchloride and closely related compounds upon the formation of persistenthaze and stable emulsions in hydrocarbon oils. The dialkyl dimethylammonium chlorides having alkyl groups consisting of at least 50% C to Cradicals reduce both haze formation :and emulsification even thoughwater extracted; whereas other closely related compounds are ineffectiveto reduce haze, have no effect upon emulsification, or are almostcompletely extracted from the oil by small amounts of water. A widevariety of commercial demulsifiers, many of which :are believed to beimidazolinium compounds and other quaternary ammonium salts, have nobeneficial effect upon haze formation and emulsification in the presenceof polymeric dispersant stabilizing additives or actually increase hazeformation in such oils. This singular effectiveness of the additives ofthe invention permits a significant improvement in the properties ofpetroleum products, simplifies the handling and storage of suchproducts, and increases their marketability.

What is claimed is:

1. A petroleum distillate fuel boiling in the range between about 75 F.and about 750 F., having incorporated therein from about 0.001 wt.percent to about 1.0 wt. percent of an 'ashless oil-soluble polymericdispersant stabilizing additive selected from the group consisting of(u) a copolymer of an alkyl chloropropylene-oxy mixed ester of anunsaturated conjugated dibasic acid and a polymerizable organic monomercontaining a vinyl group and (b) a nitrogen-containing addition-typecopolymer of an amine-free monomer containing one polymerizable ethylenelinkage and an aliphatic hydrocarbon chain of from 8 to 18 carbon atomswith a monomer containing a nitrogen atom and one polymerizable ethylenelinkage, and from about 0.00025 wt. percent to about 0.01 wt. percent ofa dialkyl dimethyl ammonium chloride in which at least 50% of the alkylgroups are C to C radicals.

2. A fuel as defined in claim 1 wherein the concentration of saiddialkyl dimethyl ammonium chloride ranges from about 0.0005 wt. percentto about 0.001 wt. percent.

3. A fuel as defined in claim 1 wherein said dialkyl dimethyl ammoniumchloride is didodecyl dimethyl ammonium chloride.

4. A fuel as defined in claim 1 wherein said dialkyl dimethyl ammoniumchloride is technical dilauryl dimethyl ammonium chloride.

5. A fuel as defined in claim 1 wherein the concentration of saidpolymeric dispersant ranges from about 0.001 wt. percent to about 0.05wt. percent.

6. A fuel as defined in claim 1 containing a tertiary alkyl primaryamine having from 8 to 18 carbon atoms per molecule in a concentrationof from about 2 to about 18 times the concentration of said copolyrner.

7. A fuel as defined in claim 1 wherein the polymerizable organicmonomer is a vinyl ester of a short chain fatty acid.

8. A fuel as defined in claim 1 wherein the polymerizable organicmonomer is a mixture of an alkyl fumarate and a vinyl ester of a shortchain fatty acid.

9. A petroleum distillate fuel boiling in the range between about F. andabout 750 F. containing about 0.001 to about 1.0 wt. percent of acopolymer of an acrylic acid ester of a C to C saturated aliphaticalcohol and a tertiary amino alkyl acrylate and from about 0.00025 wt.percent to about 0.01 wt. percent of dicoco dimethyl ammonium chloride.

10. A petroleum distillate fuel boiling in the range between about 75 F.and about 750 F. containing from about 0.001 wt. percent to about 1.0wt. percent of a copolymer of from about 2 to about l/2O parts ofisooctyl chloropropyleneoxy maleate and 1 part of a mixture of vinylacetate and tallow fumarate and from about 000025 wt. percent to about0.01 wt. percent of dicoco dimethyl ammonium chloride.

11. A petroleum distillate fuel boiling in the range between about 75"F. and about 750 F. and containing from about 0.00025 wt. percent toabout 0.01 wt. percent of dicoco dimethyl ammonium chloride and fromabout 0.001 wt. percent to about 1.0 wt. percent of a copolymer of a Cto C primary alcohol ester of methacrylic acid and? betadiethylaminoethyl methacrylate.

12. A fuel as defined in claim 11 to which has also been added fromabout 0.003 wt. percent to about 0.8 Wt. percent of a C tertiary alkylprimary amine.

References Cited in the file of this patent UNITED STATES PATENTS2,550,982 Eberz May 1, 1951 2,737,452 Catlin et all. Matt. 6, 19562,805,925 Biswell Sept. 10, 1957 2,861,874 OKel'ly et a1. NOV. 25, 1958OTHER REFERENCES Surface Active Agents and Detergents, by Schwartz etal., vol. II, copyright 1958, p. 197.

1. A PETROLEUM DISTILLATE FUEL BOILING IN THE RANGE BETWEEN ABOUT 75*F.AND ABOUT 750*F., HAVING INCORPO RATED THEREIN FROM ABOUT 0.001 WT.PERCENT TO ABOUT 1.0 WT. PERCENT OF AN ASHLESS OIL-SOLUBLE POLYMERICDISPERSANT STABILIZING ADDITIVE SELECTED FROM THE GROUP CONSISTING OF(A) A COPOLYMER OF AN ALKYL CHLOROPROPYLENE-OXY MIXED ESTER OF ANUNSATURATED CONJUGATED DIBASIC ACID AND A POLYMERIZABLE ORGANIC MONOMERCONTAINING A VINYL GROUP AND (B) A NITROGEN-CONTAINING ADDITION-TYPECOPOLYMER OF AN AMINE-FREE MONOMER CONTAINING ONE POLYMERIZABLE ETHYLENELINKAGE AND AN ALIPHATIC HYDROCARBON CHAIN OF FROM 8 TO 18 CARBON ATOMSWITH A MONOMER CONTAINING A NITROGEN ATOM AND ONE POLYMERIZABLE ETHYLENELINKAGE, AND FROM ABOUT 0.00025 WT. PERCENT TO ABOUT 0.01 WT. PERCENT OFA DIALKYL DIMETHYL AMMONIUM CHLORIDE IN WHICH AT LEAST 50% OF THE ALKYLGROUPS ARE C12 TO C14 RADICALS.